Apparatus for recording and reproducing sound



Feb. 2, 1937. A. A. THOMAS 2,069,631

APPARATUS FOR RECORDING AND REPRODUCING SOUND Filed Oct. 10, 1929 5 Sheets-Sheet l Feb. 2, 1937. A. A. THOMAS 2,069,631

APPARATUS FOR RECORDING AND REPRODUCING SOUND Filed Oct. 10, 1929 5 Sheets-Sheet 2 INVENTOR Feb. 2, 1937. A. A. THOMAS APPARATUS FOR RECORDING AND REPRODUCING SOUND Filed Oct. 10, 1929 5 Sheets-Sheet 3 Forward Feb. 2, 1937- A. A. THOMAS APPARATUS FOR RECORDING AND REPRODUCING SOUND 5 Sheets-Sheet 4 Filed Oct. 10, 1929 INVENTOR Feb. 2, 1937. A. A. THOMAS APPARATUS FOR RECORDING -AND REPRODUCING SOUND Filed Oct. 10, 1929 5 Sheets-Sheet 5 INVENTOR Patented Feb. 2, 1937 PATENT OFFICE.

APPARATUS FOR RECORDING AND BEPRODUCING SOUND Adolph A. Thomas, New York, N. Y., Radio Corporation of America,

assignor to New York,

N. 1., a corporation of Delaware Application October 10, 1929, Serial No. 398,675

31 Claims. (01. I'm-100.3)

Y My invention is for novel methods and means for recording and reproducing sound through the medium of photographic film. One of the main objects of this invention is to provide a houshold phonograph in which a long-playing film record controls the operation of electric reproducing mechanism.

The wax disk records used almost universally in phonographs since the first days of the industry are highly objectionable for several reasons. From the standpoint of the user, the main drawback of the old phonograph records is their limited capacity, which necessitates frequent changing of records. That is a nuisance and annoyance to everybody. Attempts have been made to overcome this objection by installing automatic record-changing mechanism in phonographs, but all such mechanisms are necessarily complicated and greatly add to the cost of the machine.

Among other undesirable characteristics of ordinary phonograph records, Imay mention that they break easily, are expensive to ship because of their weight and fragility, and their useful life is very short. While the new electrical recording methods and pickups have generally improved the quality of music to be obtained from existing phonographs, the fact remains that the use of a needle has certain inherent drawbacks. There is, for instance, the ever-present needle scratching which becomes more pronounced with each playing of the record. Then,needles must be frequently changed, usually for each record, an

that is a task which nobody likes.

" The foregoing and other objections and disadvantages in the old-type phonographs do not exist in the improved film phonograph of my invention. I use a photographic film on which sound waves have been recorded in a series of parallel tracks running in alternately opposite directions. At least four such tracks are recorded on each length of film, but it is possible -to have six, eight and even more sound tracks on one film if it is wide enough. A film record of that kind has an enormous acoustic capacity and can play continuously for one or more hours,

in accordance with the length of the film, which may vary from a hundred feet to a thousand and upwards. I

The reproducing mechanism of my new film phonograph comprises a rotary shutter disk having a slot for each sound track on the film. These shutter slots permit the passage of light rays through the film to aphoto-electric cell which controls a suitable loudspeaker system. when the end of a sound track is reached, the filmdriving connections are automatically reversed and the shutter disk is rotated to move the next slot into line with the next track. These operations are automatically repeated until the end of the last sound track is reached, whereupon the film automatically stops. The final winding of the film on the initial pay-out reel leaves it in condition for the next playing.

I use the film itself for controlling the filmreversing mechanism by photo-electric means which eliminate all mechanical contact with the film. Near each end of the film, at a suitable distance from the adjacent ends of the sound tracks, is a slot or small aperture through which light passes to a photo-electric cell when the end of a sound track is reached. The illuminated cell instantly closes a circuit which operates certain electromagnetic devices for reversing the film-driving connections and moving the shutter disk. These things will be fully explained later The film in my new phonograph is supported by a pair of spools, which are preferably mounted on top of the cabinet in horizontal position for easy insertion and removal. The supporting pins for the reels'are arranged on opposite sides of a box which contains the photo-electric cells of the reproducing mechanism. It is a simple matter to thread the film from the pay-out reel through the photo-electric control box and onto the takeup reel. This requires no more skill than loading of a home movie camera with which many people are familiar. After a film has been inserted, the phonograph is started by simply pressing a button, and the playing continues without-further attention until the last sound track is run ofl, whereupon the'machine stops itself. If a per-' son wants to stop the phonograph before the end of the film is reached, he need only push a stop" button mounted on the top board or in any other convenient place.

The novel features and practical. advantages of my invention will be understood from a detailed description of the accompanying drawings, in which- Fig. 1 shows a perspective of a film phonograph embodying my invention;

Fig. 2 is an enlarged sectional view on line 2-2 of Fig. 1, through the photo-electric control box; Fig. 3 represents a top plan view of Fig. 2, with the cover of the box removed;

Fig. 4 shows diagrammatically four different positions of the rotary film shutte Fig. 5 is a face view of the film shutter and a movable with the film shutter for controlling certain electrical connections, thisview being a section on line 'I-| of Fig.2;

Fig. 7a is an edge view of Figr'l;

Fig. 8 is a detached perspective of certain parts of the shutter-actuating device;

Figs. 9 and 10 show the two ends of a film bearing four record tracks running in alternately opposite directions;

Fig. 11 represents a sectional front view of the operative mechanism in the cabinet, this view being partly diagrammatic to show the circuits that control the film-driving connections and the shutter-actuating device;

Fig. 12 is an enlarged sectional view through a portion of the photo-electric control box to show the mounting of the film behind the slotted shutter disk;

Fig. 12a (on the second sheet) is a face view of the hinged film gate in the control box, this view being takenon section line l2a-|2a of Fig. 12, but on a smaller scale;

Figs. 13 and 14 are detached detail views of the mounting for the hand switch lever shown in Fig. 11, these two views being at right angles to each other;

Fig. 15 illustrates an enlarged front view of the hand switch and associated connections; and

Figs. 16 and 17 show modified forms of hand switches for starting and stopping the machine.

The-operative mechanism is housed in a cabinet III of suitable size and design. On the top board I2 is a pair of reels l3 and I4 for operatively supporting a photographic film l5 on which sound has been recorded in a plurality of tracks. A box 16 mounted'on the top board l2 between reels'l3 and I 4 contains photo-electric mechanism controlled by the different record tracks on the film. For convenience I shall refer 'to box I6 as the control box. Below the top board I2 is a chamber closed by doors l1, and the lower portion of the cabinet contains suitable reproducing appa-' ratus, including a loudspeaker. It may be assumed that the sound from the loudspeaker issues through the large front opening I8, which is covered by an ornamental grille. The space back of the doors I! may also contain the necessary vacuum tubes and other devices that go to make up an electric amplifying system for converting the light impulses in box l6 into electric impulses for operating the loudspeaker.

The control box I6 is placed over an opening IS in top board l2 and secured in any practical way, as by screws 26 passing through ears or lugs 2| at the bottom edge of the box. It is convenient to makethis box of sheet metal in two sections connected at the adjacent walls 22 and 23, which thus constitute a transverse partition. The two sections of box l6 provide a large chamber 24 and three smaller chambers 25, 26 and 21,

which are formed by a pair of partitions 28 arranged at an angle so that the central chamber is considerably wider at one end than at the other. The partitions 28 may be shaped from a single piece of sheet metal secured in place by rivets 29 or otherwise. The inside of box I6 is made light-proof by painting the walls black or lining them with black material. I6 is closed by two covers 38 and 3I-hinged at 32. If desired, a single cover may be used for both The top of box sections of the box, but the advantage of two separate covers is that either section of the box may be opened for inspection while the othersection remains closed. Furthermore. in thread- 7 ing the film through box I6, it is convenient to throw the front cover 3| back on the rear cover 36.

The film l5 passes throughrslits '33 in the sides of the control box l6 and through end slits 34 in partitions 28, as shown in Fig. 3. Between the film reels l3- I4 andthe control box are .the usual sprocket'wheels 35 and 36 for driving the film from one reel to the other at correct uniform speed. At the same time the sprocket wheels hold the film taut in alignment with the slits 33 and 34 in control box l6. These slits extend to the top of the box, so that it'isa very simple matter to insert the film after the cover 3| has been thrown back. The exposed side of wall 22 is preferably lined with soft textile material having no abrasive action on the moving film. The partition 23 carries a flat frame 3'! to which a gate 38 is hinged at 39. A spring-pressed latch 40 pivoted at 4| to the top of gate 38 engages a hook 42 on partition 23 to hold the gate firmly in normal closed position. By simply pressing down on the extension 43 of latch 40, the latter is easily released from hook 42 to permit swinging of gate 38 to open position, as indicated by the dotted lines 38' in Fig. 2. The inner face of gate 38 carries a pair of light leaf springs 44 arranged to press gently against the film l5 at its top and bottom edges, as best shown in the enadjustable mounting of rollers 35 and 36'. because that forms no part of my invention and is a detail usually found in motion picture cameras and projectors.

The bottom plate 41 of control box l6 carries a U-shaped supporting bracket indicated as a whole by 48. This bracket, which may be a single casting of aluminum-or a molding of bakelite, comprises a pair of dependingside walls 49 and 50 connected at the bottom by a cross-piece 5|. A horizontal shaft 52 journalled in the side walls 49 and 58 carries at one end a hub or short sleeve 53 to which a rotary shutter disk 54 is secured by screws 55 or otherwise. One face of disk 54 is preferably covered with a lining 56 of soft lightproof material, like black velvet, felt, silk, and the like. The transverse partition 23 in box It; is cut away or shaped to provide a recess 51 for receiving the rotary shutter disk 54, which extends into the control box through a bottom slot 58. Referring to Fig. 12, it will be seen' that disk 54 is mounted as closely as possible to the transverse wall 22, so as to cover the slot 46. The weak springs 44 hold the film l5 pressed gently against the cloth surface 56 of disk 54, whereby a lightproof contact is established between the film and the disk with a minimum amount of friction. The interposed lining 56 prevents injury to the moving film. In the present embodiment of my invention, I have assumed by way of illustration that the film I5 is provided with four record tracks A, B, C and D running in alternately opposite directions.

Referring to Figs. 9 and 10, we shall assume that 59 is the initial pay-out end of the film and photo-electric cells 88 the final wind-up end. Accordingly, the" first soundtrackAbeginsatll andthefilmisfirst played by running it in the direction of arrow 82. In other words, when the film is first placed in the machine, it is mounted on reel II, which is thus the initial pay-out reel, and I4 is the initial take-up reel on which the film is wound during the playing of sound track A. Whenthe end 88 of sound track A is reached, the film is automatically reversed (by mechanism to be described later on) and runs in the direction of arrow 84. The beginning of track B is at 88 in Fig. 10 and 'the end at 88 in Fig. 8. When the end of the second track B is reached, the driving connections of the film are again reversed and the film is again wound of! reel I8 onto reel I4 to play the third record track 0, which begins at 81 in Fig. 9 and ends at 88 in Fig. 10. The film is now once more reversed and is wound off reel I4 onto reel I8 during the playing of the last sound track D, which begins at 88 in Fig. 10 and ends at I8 in Fig. '9. It will therefore be clear that the four record tracks A, B, C and D constitute in effect one continuous track which begins at II and ends at I8.

The chamber 24 of control box I8 contains an electric lamp II mounted on a base I2 in line with the vertical slot 48 of partition 22. If de-v sired, a shield or reflector I8 may be used with lamp II to direct the light toward slot 48, which is sufilciently tall to encompass the width of the film, so that the light may strike any one of the record tracks. It is assumed that the lamp II is connected toa source of substantially constant current or potential, so as to give a uniform lightof the required intensity. The lamp II will usually be connected to the house-lighting system. If the latter uses alternating current, a suitable rectifier is interposed. In chambers 25, 28 and 21 of control box Ii are mounted three I4, I8 and I6. Several types and makes of photo-electric cells suitable for the present purpose are obtainable in the. open market, and it will therefore not be necessary to show or describe any structural details of these cells. For the purpose of this description, it is sufficient to say that each photo-electric cell has an anode and a light-sensitive cathode adapted to project a stream of electrons to the anode under the action of light. As is well known, the intensity of the electron stream depends on the quantity of light or degree of illumination that reaches the cathode. The photo-electric cells I4, I5 and I8 are each supported on a base 11 attached to the bottom-of the control box I8. On either side of the electric lamp II are two mirrors I8 and I8 arranged at such an angle as to reflect light from lamp II to the photo-electric cells I5 and I6, respectively, as indicated diagrammatically by the dash-dot lines 88 and 8I in Figs. 3 and 11. The mirrors I8 and I8 are rigidly held in frames 82 fixed to the bottom plate "of control box by screws 83, or otherwise. One of the screws 88 of each frame 82 may pass through a slot 84 curved about the other screw as a center to permit adjustment of the frames to the correct angle. The light reflected from mirror I8 reaches the photo-electric cell I5 through aligned apertures 85 in partitions 22 and 28, and the light reflected by mirror I8 passes through similar apertures 86 to "the photo-electric cell IS in chamber 21. For convenience I shall refer to the alignedslots 85 as a single slot, and the same applies to the two slots 86.

strikes the cathode I4 The light that of the photo-electric cell I4 from lamp II is controlled not only by the record tracks A,D of film II,

but also bythe rotary shutter disk 84. It is essential that only one record track be exposed to the light at one time, and this is accomplished by means of radial slits in disk 84, as best shown in Fig. 5. Since the film II in the present case bears four sound tracks, the disk 54 has four slits a, b, c and d. These slits are not only spaced from each other angularly, but are also displaced in a radial direction to correspond to the position of the soundtracks on the film. Although only a single set of slits 0-0 is necessary in disk 54, I prefer to have more than one set in order to diminish the angle through which the disk must be moved to bring successive slits into operative position in relation to the mm. The disk shown in the drawings has three sets of slits H. We may assume in Fig. 5 that the imaginary vertical with slit 0 in operative position to permit the passage of light through sound track A. The vertical length of the shutter slits is such as to permit a thin band of light to strike the sound track transversely across its entire width.

The different operative positions of shutter disk 84 are diagrammatically illustrated in Fig. 4. When the disk is in position 840., slit a is in line with sound track A of the film. In position 84b of the disk, slit b is in line with sound track B. and when the disk is in position 840, slit 0 permits the passage of light through sound track C. In the final position 84d of the shutter disk, slit d is in line with the last sound track D of the film.

The lining 58 of disk 84 is cut away at '88 opposite each slit. so as not to obstruct the passage of light. Since the disk 84 in the present instance has twelve slits, it must be moved through an angle of thirty degrees to bring the next slit into operative position. The movement of the shutter disk from one slit to the next is automatically accomplished when the end of a record track is reached. I shall now proceed to describe the shutter-actuating mechanism.

The shaft 52 which carries shutter disk 54 has a ratchet wheel 88 fixed thereon, and this ratchet wheel is operated by a pawl 88 pivoted on a pin or screw 8i projecting from a disk 82. The latter is disconnected from shaft 52 and is normally held against a fixed stop 88 by a contracting coil spring 84. One end of this spring is connected to a lug 85 projecting upward from the bottom plate 41 of box I8, and the other end of the spring is attached to a projection 88 on disk 82. The various parts mounted on shaft 52 extend into chamber 24 through an opening 81. The shaft 52 also carries a locking wheel 88 provided with peripheral notches 88 arranged to be engaged by a latch member I88. A spring arm I8I -attached to a fixed bar or bracket I82 normally presses the pointed end of latch member I88 into one of the notches 88 of locking wheel 88. The supporting part I82 may be a cross-bar or strip attached to the sides 48 and 58 of frame 48, as shown in Fig. 2. The number and spacing of the looking notches 88 correspond to the arrangement relationto the corresponding sound track of the film. 5

. Next to the locking wheel 98 on shaft 52 is an insulating disk I03 which always turns with the shaft. The disk I03 has three contact pieces I04 evenly spaced, so that their angular positions correspond to the three slits d of shutter 54. The disk I03 may be molded of bakelite or other composition material, and the contact pieces I04 may be strips of brass embedded in the material during the molding operation. Two insulated switch arms I05 and I06 are mounted on cross bar I02, which may be of insulating material. The switch arms I05-I06 may be a pair of spring blades pressing against the periphery of the insulating disk I03. Whenever the switch arms I05I06 engage one of the contact pieces I04 of disk I03, they are electrically-connected to control a circuit for stopping the film, as will pres ently be explained in detail. The arrangement of switch arms I05I06 is such that they engage one of the contact pieces I04 whenever a slit d of the shutter disk 54 is in the position of line 81 (see Fig. 5) to control the last sound track D of film I5. 1

An arm I08 is pivoted on a rod I09 supported between the side walls 49 and 50 of bracket 48. A vertical link H is pivoted to the free end of arm I08, and this link has a slot I I2 at its upper end to receive a pin I I3 projecting laterally from disk 92. A contracting coil spring II4 normally holds the lower end of slot II2 against pin II 3. One end of spring I I4 is attached to a lug I I 5 projecting from the bottom plate 41 of box IE, and the lower end of the spring is fastened to a pin II6 of link IIO. Since the disk 92 isnormally held against the fixed stop 93 by spring 94, the pin II3 constitutes a stop for the normal raised position of the pivoted arm I08. A solenoid core II1, pivotally supported from a pin I I8 on arm I 08, extends into a hollow coil II9. A lateral pin I20 on the free end of arm I08 supports a dog I2I, which is normally held against a stop I22 on arm I08 by a light coil spring I23, which is attached at one end to the arm and at the other end to the dog by pins or screws I24 and I25. The free end of dog 2I normally engages the tip of a bevelled extension I26 on latch member I00, as shown in Figs. 6 and 8. The cross-pin I20 on the free end of arm I08 may also be used as a pivot for link I I0.

When the solenoid coil II 9 is energized, the arm I08 is pulled down through a fixed angle. The first thing that happens when the arm I08 begins to move down is the unlocking of shaft 52 (and all parts mounted thereon), by the dog I2I forcing the latch member I00 out of engagement with the notched wheel 98. This unlocking takes place before the upper end of slot II2 in link IIO strikes the pin II3 of disk 92. In other words, the slot II2 permits the unlocking of shaft 52 before the arm I08 becomes coupled to the pawl disk 92, which is loose on the shaft. When the upper end of slot II2 strikes the pin II3, the continued downward movement of arm I08 under the action of coil II9 rotates the disk 92 and causes the pawl 90 to operate the ratchet wheel 89 fixed to shaft 52. The pivotal mounting of link IIO allows the same to accommodate itself to the circular path of pin II3 during the rotation of disk 92. As I said before, the arm I08 is actuated by coil II9 through a predetermined angle, which is so calculated that the shutter disk 54 is rotated through an angle equal to the distance between a pair of slits. In other words, every disk 92.

time the coil H9 is energized, the shutter disk 54 is given a kick that brings the next slit into line with its associated record track on the film.

Before the solenoid arm I08reaches the end of its downward movement, the pivoted dog I2I snaps out of engagement with the bevelled extension I26 of latch member I00, so that the latter is instantly thrown back against the periphery of wheel 98 by spring arm IOI. When that occurs, the latch member I 00 strikes the wheel 98 at some point between two notches, so that the rotation of the wheel by the continued downward movement of arm I08 is not prevented. The frictional engagement between the periphery of wheel 98 and the .tip of latch member I00 is not suillcient to interfere with the rotation of shutter shaft 52 by arm I08. When this arm reaches the limit of its downward movement, the next notch 99 of wheel 98 registers with latch member I00, whereupon the latter automatically snaps into locking engagement and holds the shutter disk 54 in correct position. After the shutter disk has thus been moved to its newv position, coil line H9 is de-energized and the tensioned coil spring II4 pulls the arm I08 back to normal raised position. During the return movement of arm I08, the free end of dog I2I rides under the tip of latch extension'I26. Just before the arm I08 reaches the end of its return movement, the dog I2I moves over the end of extension I26, whereupon the spring I23 pulls the dog back to normal position against the stop I221 Since the wheel 98 is locked before the arm I08 begins its return movement, the ratchet wheel 89 remains fixed while the pawl 90 slides over the teeth during the return of All the parts are now ready to repeat the operation above described when the coil H9 is again energized.

I shall now describe the driving connections for the film and the means by which those connections are automatically reversed at the end of each sound track. The film-driving sprockets and 36 are fixed on a pair of rotary shafts I21 and I28 which extend vertically below the top board I2 of the cabinet, as shown in Fig. 11.

The lower end of sprocket shaft I21 is supported in'a bracket I 29 carried by a horizontal partition I30 in the cabinet. A bracket I3I, also fixed on partition I30, has two vertically aligned bearings I32 and I33 for supporting the sprocket shaft I28. The upper portions of sprocket shafts I21 and I28 pass through bearings in (or supported by) the top board I2. Two bevel gears I34 one end of which is supported in bracket I 3| and the other end in a bracket I38. A small electric motor I39, supported on partition I30, has a driving shaft I40 which carries a worm I permanently in mesh with a worm gear I42 fixed on the countershaft I31.

A clutch ring I43 is keyed on sprocket shaft I28, so as to be slidable into engagement with the teeth of either bevel gear I34 and I35. An annular groove on clutch ring I43 receives the forked end of an operating lever I44, according to the usual practice. The lever I44 is pivoted at I45 on a suitable support (not shown), and the free end I46 of the lever is in the form of (or otherwise carries) an armature arranged to operate between a pair of electromagnetic coils I 41 and I 48. A contracting coil spring I 49 is connected at one end to a fixed point I50, and at the other end to a, point I5I on lever I44. The arrangement of spring I49 is such that it holds the clutch lever I44 in either of its actuated'positions. When coil I41 is energized, the clutch ring I43 is moved into operative engagement with bevel gear I34 to rotate the sprocket shafts I21 and I29 in-a direction to unwind the film from reel I3 onto reel I4. This may be called the. forward movement of the film, as indicated by. the arrow at the top if Fig. 11. When the opposite coil I49 is energized, the lever I44 is rocked the other way to throw the clutch ring I43 into engagement with bevel gear I35, whereby the rotation of the film is reversed, so that it is unwound from reel I4-onto' reel I3. The transmission connections between the motor shaft I40 and the sprocket shafts I21--I29 are made to run as silently as possible.

The film reels I3 and I4 are mounted on apair of stud-shafts I52 and I53, which may be journalled in the top board I2, or otherwise suitably supported. A pivoted weight I54 at the upper end of each reel shaft permits the easy insertion and removal of the reels, and at the same time holds them against vertical displacement during the operation of the machine. A grooved pulley I55 is mounted on the lower end of reel shaft I52, and a similar pulley I55 is carried by the lower end of reel shaft I53. Thesprocket shafts I21 and I29 are provided with grooved pulleys I51 and I59,.respectively. The aligned pulleys I55 and I51 are connected by a driving band or belt I59, and a similar belt I connects the pulleys I and I59. The driving belts I59 and I50 are preferably of elastic .material, like rubber, finely wound coil springs, rubberized fabric, and other material suitable for the purpose. The tension of belts I59 and I50 is such that they permit slipping of the pulleys to allow the reels I3 and I4 to accommodate themselves to variable speeds during the winding and unwinding operations. A belt or chain I5I connects the sprocket shafts I21 and I29 for simultaneous operation at the same speed. v

The gear reduction between the motor shaft I40 and the sprocket shafts I21I29 is such that the film is moved at the proper linear speed through the photo-electric control box I5. The speed of the film during the reproduction should be substantially the same as the speed used in the recording operation.- It is understood that the speed of the film across its optical field should be uniform, and it is therefore necessary that the motor I39 operate at constant speed. The rate at which the film is paid out from one reel and wound onto the other will vary continuously during the movement of the reels, but the rectilinear speed of the film through the control box is constant. For this reason it is necessary to have a certain amount of play in the film between each reel and the adjacent sprocket wheel. This is usually accomplished by a so-called looping of the film, as may be found in every motion picture camera and projector. I have not deemed it necessary to show the looping of the film, because it is a detail well understood and its omission simplifies the drawings.

If we assume the reel I3 to be the initial payout reel, the other reel I4 becomes the driving reel during the playing of sound tracks A and C, and is positively actuated through belt I50 to pull the film off reel I3. During thisforward drive of the film, the belt connection I59 between shafts I21 and I52 allows therotation of reel I3 at the unwinding of the film,

varying speeds for shaft I21 rotates at constant while the sprocket speed. When the film is wound of! reel I4 onto reel I3 during the playing of sound tracks B and D, it is reel I3 that is positively driven. and reel I4 allows the film to be pulled off as required.

I may incorporate into the machine a suitable 5 arrangement for automatically tightening the belt I50 when reel I4 takes up the film during the playing of sound tracks A and C, and tightening the other belt I59 when reel I3 takes up the film for sound tracks B and D. An automatic belt- 10 tightening device suitable for that purpose is disclosed in my copending application Serial Number 351,240.

Referring to Figs. 11, 13, 14 and 15, there is a hand lever I52 projecting'through a slot I53 in 15 top board I2. This lever or finger piece is pivoted on a pin I54 carried by a bracket or block I55, which may conveniently be attached to the underside of the top board. The lever I52 carries a' spring-pressed ball or button I55 adapted to snap 20 intorecesses I51 and I59 in bracket I55 for frictionally holding the lever in either of two actuated positions. When the lever I52 is vertical, as shown in dotted lines in Fig. 13 and in full lines in Fig. 15, the button I55 Is held pressed in 25 recess I51. When the lever I52 is in the stop position I52a (see Figs. 13 and 15), the button I55 is forced into recess I59. The lower extension I59 of finger piece I52 is arranged to actuate a pair of spring arms I10 and "I. The spring 3 attached to the bracket I55. When the arm I14 40 is in normal raised position against stop I19, the

freeend of the armis above the bevelled catch I13. When the coil I11 is energized, the arm I14 is pulled down into the position indicated at I14,

and catch I13 locks the arm in that position. 45

When the hand lever or finger piece I52 is moved into the start" position indicated by dotted lines I52b, the extension I59 moves the locking spring I10 into position I10, whereby the solenoid lever I14 is released and quickly pulled back to 50 normal position by spring I19.

Still referring to Fig. 15, the spring arm I1I. is normally in contact with an adjacent spring arm I90. These two arms are mounted on an insulating support I9I and constitute a normally 55 closed switch in the circuit of the electric motor I39, as I shall presently explain. The solenoid lever I14 is operatively connected to switch arm I90 through an insulating piece I92, which is attached to both of those parts. 3 member I14 is held in raised position by spring I19, the connecting piece I92 holds the switch arm I90 pressed against the associated arm I" to close the motor circuit. When the coil I11 is energized and pulls down the arm I14, the connected switch member I90 is pulled down away from switchmember "I, so that the motor circuit is broken. The open position of switch member I90 is indicated by the dotted lines I90.

It will thus be seen that, as long as the solenoid 7 0 arm I14 is held locked in position I14 by catch I13, the motor circuit remains open. When the finger piece I52 is moved to start position I521), the arm I14 is released and the motor switch HI-I90 is automatically closed. By moving the I11, or the arm As long as the co finger piece I62 to stop position I62a, the extension I69 engages the free end of spring arm HI and raises the latter into position I1I' to open the motor circuit. It should be noted that the finger piece I62 is locked in stop position I62a, so that the motor circuit remains open until the finger piece is moved to normal vertical position. However, when the finger piece I62 is moved to start position I62b for closing the motor circuit, the spring arm I10 moves the finger piece to normal vertical position as soon as it is released. In other words, when a person wants to start the machine, he simply moves the finger piece I62 to position I62b and then lets go.

I now come to the circuit connections in Fig. 11. One side of the motor is connected to a supply main I83 attached to a plug I84, which is intended to be inserted in an ordinary house-lighting socket. The other side of the motor is connected by conductor I85 to switch arm l1I. The adjacent switch arm I80 is connected by a conductor I86 to the other service main I81. The rectangular outline I88 indicates diagrammatically any suitable form of electric amplifying apparatus to which current is supplied through conductors I89 connected to the house-lighting circuit. The anode 14a and cathode 140 of the photo-electric cell 14 are connected by conductors I90 to the amplifying apparatus I88, which utilizes the current fluctuations in circuit I90 to operate or control a loudspeaker I9I. At the present time, the most popular loudspeaker is the so-called moving coil type, which utilizes a small cone diaphragm, but any approved form of loudspeaker may be used. The amplifying apparatus I 88 may be similar to the well known radio circuits employing detector tubes and amplifying tubes. In this case, the current fluctuations in circuit I90 of cell 14 produced bylight variations on cathode 14c constitute the input for the amplifying apparatus I88. These input current variations are sufiiciently amplified to operate the loudspeaker I9I with the requisite degree of power and fidelity of tone. A main on-and-off switch I92 may be employed to cut off not only the film-driving motor I39, but also the amplifier I88, so that all circuits are opened and no waste of current is possible. The switch I92 may conveniently be mounted on the top board I2 of the cabinet, or it may be located at a distance from the'cabinet, as in a small box that may be placed anywhere. It is understood that the switch I92 is closed to permit operation of the machine through the auxiliary start-and-stop switch lever I62. V

One end of the shutter-operating coil H9 is connected by conductor I93 to the cathode 15c 01 the photo-electric cell 15, and the anode 15a of this cell is connected to the positive side of a battery I94 or other source of constant current. The other side of the battery I94 is connected by a conductor I95 to one end of coil I48. The

clutch-operating coils I41 and I 48 are joined at one end by conductor I96 which is connected by conductor I91 to the other end of coil II9. It is thus seen that coil I I9 is connected in series with either of the clutch coils. A conductor I98 con nects one side of clutch coil I41 with the negative terminal of a battery I99 or other source of constant current. One side of coil I11 is connected to switch arm I05 by conductor 200, and the other side of that coil leads to conductor I98 through connection 20I. A conductor 202 connects the cathode 160 of photo-electric cell 16 to conductor I93, which leads tothe shutter-operating coil II9. A wire 203 connects the switch arm I06 to conductor 202. The anode 16a of cell 16 is connected to the positive side of battery I99. In actual practice, the photo-electric cells 15 and 16 are preferably connected to the houselighting system (through a rectifier if necessary), and I have shown the batteries I94 and I 99 to simplify the circuit connections in Fig. 11.

We shall assume that the film is running oi! reel I3 onto reel I4 (that is, from left to right in the top portion of Fig. 11), for the playing of the first sound track A. This means that the shutter disk 54 is in the position shown in Fig. 5, with slit a in operative position. The sprocket shafts I21I28 and the reel shafts I52-I53 are driven by the electric motor I39 through gear connections I 36I34. To prevent possible con-,-

Therefore, while the forward run of the filmiis from left to right in a front view, this direction becomes right to left in a view from the rear. This accounts for the two Forward arrows at the top and bottom of Fig. 11 pointing in opposite directions. As the sound track A moves past the aligned light apertures 45 and 46, the degree or intensity of the light that strikes cathode of photo-electric cell 14 from lamp II varies in accordance with the characteristic markings of the sound track. At the present time there are two ways of recording sound on a photographic film: either by varying the intensity of light across a band of uniform width, or by exposing a band to uniform light but varying its width. The sound tracks shown diagrammatically in the drawings are intended to represent any practical method of recording sound or other vibrations on a photographic film. The variations of light on cathode 140 as controlled by the sound track produce electric impulses which are amplified in apparatus I88 for operating the loudspeaker I 9| Let us now see what happens when the end of sound track A is reached. Referring to Figs 9 and 10, it will be seen that the film is provided near its ends with apertures or windows 204 and 205, which are located in an opaque band or section 206 of the film. The apertures 204 and 205 may be holes punched in the film, or they may simply be transparent spots in the opaque band 206, which runs between the middle sound tracks B and C. If the entire area of the film outside the sound tracks is made opaque, no separate band 206 is necessary. When the end 63 of sound track A is reached in its operative fiield, the window 205 is in line with aperture 85 in the control box, so that light rays from lamp 1| strike the cathode of photo-electric cell 15. This closes the circuit through coils H9 and I48 as follows: starting at the plus side of battery I94, across the electronic conducting space 15-150 of cell 15, conductor I93, coil II9, conductor I91, coil I48, and through conductor I95 back to the battery. 0011 H9 on being energized, operates the shaft 52 and moves the shutter disk 54 to bring slit B into operative position for sound track B, which begins at 65 (see Fig. 10.) The operating connections between coil H9 and shaft 52 have already been explained, so need not be repeated. The movement of shutter disk 54 is accompanied by a like movement of contact disk I03, which is fixed on shaft .52. Disk I03 is marks in Fig. 11, each movement in the present instance being one-twelfth of a revolution. I

might explain here that the arrow associated with the shutter disk 64. in Fig. 5 points in the opposite direction to the arrow of. contact disk I03 in Fig. 11. Those two disks always .rotate in the same direction, but we are looking at the shutter disk in Fig. 5 from the front of the cabinet, while in Fig. '11 the contact disk I03 and locking wheel 99 are viewed from the opposite direction.

when the coil I48 is energized at the end of sound track A, it throws the clutch ring I43 against the bevel gear I35 to reverse the rotation.

of sprocket shafts I21--I20 and reel shafts I52I53. The film now runs in the direction of arrow 64 (see Fig. 10) for the playing of the second sound track B,,and is wound of! reel I4 onto reel I3. When the end of sound track B is reached the window 204 in film I5 is in line with aperture 96 in the control box and light from lamp 1I strikes the cathode 16c of photo-electric cell 16. This closes the circuit of battery I99 through coils H9 and I41 as follows: starting at the positive side of battery I99, across the electronic conducting path 16a-16c of cell 16, conductors 202 and I93, coil II9, conductor I91, coil I41, and through conductor I98 back to the battery. Coil H9 again gives the shutter disk 54 a kick forward to bring slit c into line with the third sound track C, which begins at 61 (see Fig. 9). At the same time, the contact disk I03 is moved through another one-twelfth of a revolution. When the coil I41 is energized, it shifts the clutch ring I43 back into engagement with bevel gear I34, so that now the film is wound ofif reel I3 onto reel I4 for the playing of the third sound track C.

When the end 69 of sound track C is reached, the window 205 of the film registers with aperture 85 in control box I6 and the photo-electric cell 15 is activated by light rays from lamp II to close the .circuit of battery I94 through the shutter-actuating coil H9 and the clutch-operating coil I46. As these circuits were traced in connection with sound track A, it will not be.necessary to repeat them here. The third kick received by the shutter disk 54 brings slit d in line with the last record track D. When slit D moves into operative position, the switch arms I05--I06 engage one of the contact pieces I04 of disk I03. This, however, does not close the circuit of battery I99 through coil I11, because the photoelectric cell 16 is inactive until the end of track D is reached. During the playing of the fourth record track D, the film is wound oiI reel I4 onto reel I3, which is the initial pay-out reel. When the end 10 of sound track D is reached, the window 204 of the film is in line with aperture 66 in control box I6 and light from lamp 1| strikes the cathode 160 of cell 16. The circuit of battery I99 is now closed again through coils I I9 and I41, as previously explained.- This fourth kick of the shutter disk 54 brings slit :1 of the next set of slits into line for playing the first record track A of the next film. The energizing of coil I41 moves the clutch ring I43 into engagement with bevel gear I34. Consequently, when the next film is inserted in the machine, the driving connections are in condition to wind the film oII reel I3 onto reel I4, so that no adjustments are necessary by the operator.

At the end of the last sound track D, the circuit of battery I99 is closed through coil I11, because the switch members I05 and I06 are connected by one of the contact pieces I04. The energized coil I11 opens the motor switch I1I-I90, as already described in detail in connection with Fig. 15. The film is thus automatically stopped when the end of the last sound track is reached. The motor switch I1I-I30 remains open because the arm I14 is locked in down position by the latch member I10. To start the motor again, it is only necessary to move the finger piece I62 into position I62b, as previously explained. The short strip of film that may remain between the reels I3 and I4 after the last soundtrack has been played, is readily wound by hand onto reel I3.beiore the latter is removed from the machine. A sheli 201 in the cabinet may be used for holding a supply of additional reels 209.

In Fig. 16 I use two separate buttons 209 and 2I0 for starting and stopping the motor by means of switch I1II90. Those parts of Fig. 16 that correspond to similar parts, in Fig. 15 are indicated by like reference numerals, so that a portion of the description of Fig. 15 is also applicable to Fig. 16. The latch member I10 has a bevelled extension 2 arranged in the path of the bevelled lower end 2I2 of the start button 209. The arm or lever I14 is directly below the stop button 2I0, which may also form a stop for the upward movement of the arm by spring I19.- Coil springs 2I3 normally hold the push buttons 209 and 2I0 in upper position. When the start button 209 is pushed down, latch member I10 is moved into releasing position I10'. If the solenoid arm I14 was held in down position by member I10, it will now be released and moved up to normal position under the action of spring I16, so that the motor switch I1II9,0 is closed, as explained in connection with Fig. 15. When the stop" button 2I0 is depressed, the arm I14 is forced down into the position shown in full lines in Fig. 16 to open the motor switch I1I-I80, so that the machine stops playing. The arm I14 is held locked in down position by the latch member I10, whereby the motor circuit remains open until the start button 209 is depressed.

The downward movement of buttons 209 and 2I0 is limited by the annular shoulders 2I4 in top board I2 and the collars 2I5 on the buttons. In some respects the double button arrangement of Fig. 16 for starting and stopping the machine is preferable to the single finger piece I62 of Fig. 15. It will be observed that the buttons may be released immediately after being .Iully I, w depressed.

In the modification of Fig. 17, the motor switch I1II90 is controlled electrically by a pair of push buttons 2I6 and 2I1, which may be mounted at any convenient point on the cabinet, usually on the top board. The start button 2I6 is mounted on a spring arm 2I6 adapted to engage a stationary contact member 2I9 for closing the circuit of battery 220 through a solenoid 22I. A conductor. 222 connects 'one side oi. battery 220 with switch contact 2I9, and a conductor 223 leads from one side of coil 22I to the movable switch arm 2I8. The other side of coil 22I is connected at 224 to the battery lead 225. The stop button 2I1 is mounted on a spring arm 226 which is connected by a conductor 221 to one side 0! coil I11. The other side of this coil goes to the battery lead 225.

A conductor 220 connects one side-o! battery position and yet permits the same to move into the other position. In other words, the catch 230 releasably holds the arm I'll in raised position to keep the motor switch I'll-I80 closed, or in lowered position I H to keep the motor switch open.

Still referring to Fig. 17, when the start button 216 is pushed down, the circuit of battery 220 is closed through coil 22l which pulls the arm I14 up to close the motor switch l1l-,l8-

This switch remains closed until the stop but- .ton 2| 1 is pushed down to energize coil "1,

which pulls the arm I14 down to break the motor switch I'll-I80. The start and stop buttons 2H5 and 2H need only be held down for an instant to start the machine and stop it whenever desired. The manual control of the motor switch by means of the buttons U6 and 2|! is independent of the automatic stopping of the motor when the end of the last sound track is reached. The purpose of the finger piece I62 in Fig. 15 and the start and stop buttons in Figs. 16 and 17 is to enable a person to stop the machine at any time and to start it again when desired. In'actual practice, coil 22l will be connected to the house-lighting system when plug I84 (see Fig. 11) is inserted. The battery 220 is shown merely to simplify the circuit connections in the drawings.

Although I have shown a single lamp H for controlling the operation of cells 14, 15 and 16, it isevident that a separate lamp may be used for each cell, thus dispensing with the mirrors 18 and 19. Referring to Fig. 3, the path of light rays has been diagrammatically indicated without taking into account the use of lenses ordinarily employed in concentrating the light and directing it properly against the light-sensitive electrode of each cell. Since the use of such lenses in optical recording and reproducing systems is well understood, I have omitted them to simplify the drawings and specification. Instead of supporting the film reels l3 and I4 on the top board of the cabinet, I may mount them on a vertical panel behind the doors l1,- with a corresponding re-arrangement of the control box and driving connections. I think, however, that the reels are manipulated most easily by mounting them on the top board, as shown in Fig. 1. The shutter 54 may be in the form of an endless band having the proper slits and intermittently movable in the direction of its length, but I prefer a rotary disk because it is easier to mount and simpler to operate. This disk may also be used with a film having only two sound tracks. The photo-electric control of the motor connections and shutter 54 by the film itself has a decided practical advantage, because no movable parts or switch-operating members are in mechanical contact with the fil m. This eliminates wear on the film and injury to its sensitized surface.

It will be clear from the foregoing description that I have provided a phonograph in which a film with a multiple sound track is played continuously from the beginning of the first track to the end of the last track without attention by the operator. The interruptions between the ending of one track and the starting of the next are so short as to be barely perceptible, so that the playing is practically continuous. If a musical composition is recorded, the intervals of jumping from one track to the next may be-pauses in the music, so that even these brief interruptions would not be noticed. Of course, it is not necessary that all the tracks shall relate to the same subject matter. For example, track A may be an orchestral number, track B a speech, track C a song, and so forth. The number of tracksrecorded on a film obviously depends on the available width of film and on the individual width of the tracks. It is doubtless possible to make a sound film with six or eight record tracks and of such-length as to play continuously for several hours without attention by anybody. Such long playing films may bear the complete score of musical compositions of great length, which heretofore had to be abbreviated on phonograph records. It is also feasible to record complete operas, plays and books on films in accordance with my invention. While I prefer an even number of record tracks on a film, an odd number (like 3, 5, etc.) may be used; but an even number of tracks brings the film back to initial position at the conclusion of the run. If a person happens to be out of the room when the end of the last sound track is reached, the film is automatically stopped and the motor circuit remains open until somebody moves the switch to starting position. Although the apparatus shown in the drawings has been described for the reproduction of sound from the film, I want it understood that the same or similar apparatus can be employed for recording on the film.

My invention is by no means limited to household phonographs, and I may say it finds particular usefulness. in the field of talking movies. Two methods of sound accompaniment for motion pictures are employed at the present time:

in the phonographic method, the sound is reproduced from a wax record operated in synchronism with the picture; in the optical method, the picture film carries a sound track alongone edge. The maximum playing time of a large-sized wax record is about twelve minutes, which is usually less than the running time of a standard-length picture reel. Hence, the necessity of changing from one record to another while the picture is on. This requires either a special attendant or automatic switching mechanism of great cost. Recording the sound alongside of v the picture on the same film is objectionable forseveral reasons, principally because the sound track usually requires difierent treatment during exposure, developing andprinting of the film than the picture itself. Now, the multiple-track film of my invention can carry the sound accompaniment for several reels of pictures. To illustrate: a standard motion picture film has a length of about 900-1000 feet, and the regulation number of reels is five for a feature picture. ally run for one hour and a quarter. A single 1000-foot film with six record tracks has an acoustic capacity for a talking movie of five or six reels, and it is possible to go beyond that.

Although I haveshown and described a specific machine, I want it understood that my in- These pictures usuvention is not limited to the details set forth.

I know, I am the first to provide a recording or reproducing machine in which a photographic film has more than two sound tracks running in alternately opposite directions, in combination with means whereby the sound tracks are automatically recorded or played as a substantially continuous track, and I claim this idea in a fundamental way.

I claim as my invention:

1. In optical apparatus utilizing a film which has a plurality of record tracks, a rotary member having a plurality of light apertures movable in an endless path, means whereby only one track can be exposed to said apertures at a time, each aperture being arranged in operative relation to one of said tracks, means for positively locking said member in each operative position, an electromagnetic device for operating said member, and connections whereby said device when energized actuates said locking means to releasing position before operating said member.

2. In acoustic apparatus, the combination of a film having a plurality of reversely arranged sound tracks, a source of light and a photoelectric element arranged on opposite sides of said film in operative relation thereto, mechanism for driving said film forwardly and reversely, a movable-shutter for exposing only one track at a time to light rays from said source, and photoelectric means optically controlled by the film for operating said shutter, said photo-electric means including a light-sensitive cell and abeam of light sent thereto through the film in a direction substantially at right angles to the face oi. the

film.

3. In optical apparatus utilizing a film with a photographic record thereon, the combination of means for supporting a length of said film for operative movement in an optical field, mechanism for driving said film, a photo-electric cell, means for sending a. beam of light to said cell in a direction substantially at right angles to the plane of movement of the film in the optical field, said cell and film being so arranged that the film moves fiatwise across the path of said light beam, means on the film adapted to act upon said light beam when a point on the moving film reaches a predetermined position to aiiect the condition of said cell, and an electric circuit controlled by the affected cell for automatically stopping said driving mechanism, which remains inoperative so that the film is held stationary.

4. In optical apparatus utilizing a film with a photographic record thereon, the combination of a pair of reels for supporting a length of said film for operative movement in an optical field, reversible mechanism opposite directions for unwinding and rewinding, a photo-electric cell, means for sending a beam of light to said cell in a direction substantially at right angles to the plane of movement of said film in the optical field, said cell and film being so arranged that the film moves fiatwise across the path of said light beam, means on the film adapted to act upon said light beam when a point on the unwinding film reaches a predetermined position to affect the condition of said cell, and electric means controlled by the affected cell for automatically reversing said driving mechanism to rewindthe film on its original reel.

5. In optical apparatus utilizing a film with a photographic record thereon, the combination of a pair of reels for supporting a length of said film for operative movement in an optical field, reversible mechanism for driving said film in opposite directions for unwinding and rewindlng, a pair of photo-electric cells, means for sending a separate beam of light to each cell in a direcfor driving said film in tion substantially at right angles to the plane of movement of said film in the optical field, the two cells and the film being so arranged that the film moves fiatwise across the path of each light beam, means on the film adapted to act upon one of said light beams when-the film has been unwound to affect the condition of one of said cells, an electric circuit controlled by the affected cell for automatically reversing said driving mechanism to rewind the film, other means on the film adapted to act upon thesecond light beam when the film has been rewound to aifect the condition of the second cell, and means whereby the second cell when so afie cted automatically stops the driving mechanism.

6. In film-controlled optical apparatus of the class described, an intermittently rotatable shutter having a series of slits and covered on one side with soft material, and means for supporting a moving film substantially in contact with the covered side of said shutter.

7. The combination of a film supported for operative movement and having a plurality of record tracks, optical reproducing mechanism associated with said film, a rotary shutter disk having slits for exposing only one track at a time to said mechanism, said disk being mounted substantially in contact with one side of the film, the contacting side of said disk being covered with soft material to prevent injury to the film.

8. In film-controlled optical apparatus of the class described, a rotary shutter arranged to cocupy a plurality of operative positions, means for positively locking the shutter in each operative position, and electromagnetic means for automatically actuating said locking means to releasing position at predetermined intervals.

9. In film-controlled optical apparatus of the class described, a movable shutter arranged to occupy a plurality of operative positions, filmcontrolled mechanism for moving said shutter at predetermined intervals from one position to the next, means for positively locking the shutter in each operative position, and means operated by said mechanism for releasing said locking means.

10. In film-controlled optical apparatus of the class described, a rotary shutter arranged to occupy a plurality of operative positions, electromagnetic mechanism for rotating said shutter at predetermined intervals from one position to the next, means for positively locking the shutter in each operative position, and means controlled by said mechanism for releasing said locking means.

11. In apparatus of the class described, a movable shutter having a plurality of light apertures so arranged that only one aperture at a time is in operative position, connectionsfor actuating the shutter from one position to the next, means independent of said connections for automatically locking the shutter in actuated position, and means controlled by said connections for releasing said locking means before the shutter is actuated.

12. In acoustic apparatus, the combination of a film having a plurality of sound tracks, an electric motor for operating said film, optical reproducing mechanism associated with said film, means controlled by the film for successively exposing said tracks one at a time to said mechanism, said means including a movable member automatically operated when a new track is played, a switch closed by said member when the last track is reached, and circuit connections controlled by said switch for automatically deener- 13. In acoustic apparatus, the combination or a film having a'p'lurality 01' sound tracks, an electric motor for operating said film, optical reproducing mechanism associated with said fihn, a movable shutter ior successively exposing said 1 tracks one at a time to said mechanism, an electromagnetic through,

said member tromagnet energized at predetermined intervals tooperate said shutter irom one position to the next, a movable member operated whenever said electromagnet is energized, a switch closed by when the last track is reached, and circuit connections controlled by said switch for automatically de-energizing said motor and stopping the film when the last track has been played.

14. In apparatus of the class described, the combination of means for operatively supporting a moving film, an electric motor for driving said film, a switch in the motor circuit, means controlled by the fihn for opening said switch at a predetermined moment, said switch remaining in opened condition, and a manually operable member for closing said switch at will independently of the film.

15. In acoustic apparatus, the combination of a record member, reproducing means controlled by said member, an electric motor for operating said member, a switch in the motor circuit, electromagnetic means controlled by said record member for automatically opening said switch to stop the motor when said member is played through, and manually operable means for closing the opened switch to start the motor and operate said record member.

16. In acoustic apparatus, the combination of a record member, reproducing means controlled by said member, an electric motor for operating said member, a switch in the motor circuit, electromagnetic means controlled by said record member for automatically opening said switch to stop the motor when said member is played through, and ahand-operable switch for energizing said electromagnetic .means independently of said record member to open the motor switch at will, said motor switch remaining in either position until actuated to the other position.

17. In acoustic apparatus, the combination 01' a record member, reproducing means controlled by said member, an electric motor for operating said member, a switch in the motor circuit, electromagnetic means controlled by said record member for to stop the motor when said member is played through, vmanually operable means for closing the opened switch to start the motor and operate said record member, and connections whereby said manually operable means is adapted to open the closed switch independently 01 said electromagnetic means.

18. In acoustic apparatus, the combination of a record member, reproducing means controlled by said member, an electric motor for operating said member, a switch in the motor circuit, elecmeans controlled by said record member for automatically opening said switch to stop the motor when said member is played manually operable means for closing the opened switch to start the motor and operate said record member, a push button for closing the opened switch, a second push button for opening the closed switch, and means whereby said switch remains in either position until actuated to the other position,

19. In optical apparatus utilizing a film which has a plurality of record tracks, a movable shutautomatically opening said switch start the apparatus, and a second shutter, said means including an electric motor,.

a member movable with said open switch closed. by said shutter is in position for the second normally open switch in series with said other switch and adapted to be closed when the end of the last track is reached, an electromagnetic device energized by the closing of both oi said switches, and means for stopping the motor when'said device is energized.

20. In acoustic apparatus, the combination oi means for operatively supporting a film provided with a plurality of sound tracks running in alternately opposite directions, anelectric motor having connections for operating said film in both directions, optical reproducing means associated with said film, a movable shutter ior exposing only one track at a time to said mechanism, means controlled by the film tor automatically operating said shutter and reversing said driving connections at the end of each sound track, a switch in the motor circuit independent of said reversing connections, and electromagshutter, a normally member when the last record track, a

netic means automatically energized when the end of the last track is reached to open the motor switch.

21. In acoustic apparatus, the combination i means for operatively supporting a film provided with a plurality of sound tracks running in alternately opposite directions, reproducing mechanism associated with said film, an electric motor for driving said film in opposite directions, means for subjecting said mechanism to the control of only one sound track at a time, film-controlled connections for automatically reversing the operation of said motor at the end of each track, a separate switch independent of said reversing connections, means for closing said switch when the end of the last track is reached, and an electromagnetic device energized by said closed switch to open the motor circuit.

22. In acoustic apparatus, the combination of a record member, reproducing means controlled by said member, an electric motor for operating said member, a switch in the motor circuit, electromagnetic means controlled by said record member for automatically opening said switch to stop the motor when said member is played through,

a hand-operable switch for energizing said electromagnetic means independently of said record actuated to the" other position, other electro-' magnetic means for closing the motor switch to hand-operable switch for energizing said last-mentioned electromagnetic means, said motor switch remaining in either position until actuated to the other position.

23. In film-controlled apparatus, the combination of a pair of reels for supporting a film for movement lengthwise in alternately opposite directions, an electric motor in reversible driving relation to said film, means for automatically reversing the driving movement .01 said motor when the film is unwound from its original reel, other means for automatically reversing the driving movement of said motor when the film is rewound on its original reel, each of said reversing means including an electromagnetic device and a photoelectric cell for controlling said device, means whereby one oi? said cells is controlled when the film moves in one direction, and means whereby the other cell is controlled when the film moves in the other direction.

24. The combination of means for supporting a length of phonographic film for movement in opposite directions, reversible driving connections for said film, photoelectric means controlled by the film when unwound for reversing said connections, and other photoelectric means controlled by the film when rewound for again reversing said connections, each of said photo electric means including a beam of light in the path of the moving film and substantially at right angles to the face of the film.

25. In sound-reproducing apparatus, the combination of means for operatively supporting a length of film having a sound track thereon, driving connections for said film, optical reproducing mechanism associated with said film and controlled by the sound track thereon, and photoelectric means independent of said mechanism and controlled by the film itself in normal operative condition for controlling said driving connections, said photoelectric means including a beam of light in the path of the moving film and substantially at right angles to the face of the film.

26. In acoustic apparatus, the combination of means for operatively supporting a film provided with a plurality of sound tracks running in alternately opposite directions, driving connections for said film, optical reproducing mechanism associated with said film, and means optically controlled by said film in normal operative condition for automatically reversing said driving connections when the end of a record track is reached, said reversing means including photoelectric means separate from said reproducing mechanism, and said photoelectric means including a beam of light in the path of the moving film and substantially at right angles to the face of the film.

27. In film-controlled apparatus, the combination of means for supporting a film for movement lengthwise, in alternately opposite directions, means for automatically reversing the film when unwound, means for automatically reversing the film when rewound, each of said reversing means including a photoelectric cell optically controlled by the film itself in normal operative condition, and means controlled by one of said photoelectric cells for automatically stopping the film in rewound condition after it has been reversed a predetermined number of times.

28. In apparatus of the class described, the combination of means for supporting a film for operative movement,- said film having at least four sound tracks running in alternately opposite directions, optical reproducing mechanism associated with said film, a movable shutter for exposing only one track at a time to said mechanism, driving connections for automatically reversing the movement of said film at the end of each record track, an electromagnetic device for automatically operating said shutter wherever said driving connections are reversed, each movement of the shutter exposing the next record track to said mechanism, a photoelectric cell independent of said optical reproducing mechanism and controlled by the film in normal operative condition for controlling said device, and means for sending a beam of light through the film to said cell in a direction substantially at right angles to the face of the film.

29..In acoustic apparatus, the combination of means for operatively supporting a film provided with a plurality of sound tracks running in alternately opposite directions, driving connections for said film, optical reproducing mechanism associated with said film, means optically controlled by said film in normal operative condition for automatically reversing said driving connections when the end of a record track is reached, said reversing means including two photoelectric cells independent of said reproducing mechanism, one cell being arranged to cause unwinding of the rewound film, and the other cell being arranged to cause rewinding of the unwound film, and means for sending a beam of light through the film to each cell in a direction substantially at right angles to the face of the film.

30. In acoustic apparatus, the combination of means for operatively supporting a film provided with a plurality of sound tracks running in alternately opposite directions, driving connections for said film, optical reproducing mechanism associated with said film, means optically controlled by said film for automatically reversing said driving connections when the end of a record track is reached, said reversing means including two photoelectric cells independent of said reproducingmechanism, one cell being arranged to cause unwinding of the rewound film and the other cell being arranged to cause rewinding of the unwound film, and a single source of light for optically energizing said reproducing mechanism and both of said cells.

31. In film-controlled acoustic apparatus, the combination of means for supporting a film having a plurality of sound tracks running in alternately opposite directions, reversible driving connections for said film, photo-electric reproducing mechanism controlled by said mechanism, means for holding said film, and mechanism again-st relative lateral displacement, a rotary shutter for exposing only one track at a time to said mechanism, a switch controlled by the film itself at the end of each sound track, electromagnetic means energized by the operation of said switch for operating said reversing connections and said shutter, and other electromagnetic means automatically controlled by the film at the end of the last track to stop said driving connections.

ADOLPH A. THOMAS. 

